The statements in this section merely provide background information on the present disclosure and do not necessarily constitute the prior art.
Visible light communication is wireless communication technology for transmitting visible light data, which is configured in an on/off signal pattern, using the fast response speed of a lighting device. For visible light communication, when the lighting device is given a visible light communication function and installation position information about the lighting device is used, various communication supplementary services may be provided. For example, a communication supplementary service may be employed as a service for measuring the position of a terminal in a room, and may also be employed as a service for transmitting information from the lighting device to the terminal.
In order for visible light communication to provide various services as described above, communication devices used for visible light communication are required to be registered with a server. When a plurality of lighting devices is present, the lighting devices may be registered with the server, and the server may classify and deliver data to the respective lighting devices. Further, when visible light communication is used for a positioning service, the position of a terminal near the lighting device may be measured if the position of the lighting device has been registered. If the terminal has been registered with the server in advance, the server may determine whether the terminal requesting a specific service is a registered terminal to selectively provide the service.
According to the conventional visible light communication technology, the lighting device is capable of transmitting data to the terminal, but the terminal is not allowed to transmit data to the lighting device. Therefore, in registering the lighting device and the terminal with the server, the lighting device is required to be separately registered with the server, and the terminal is also required to be directly and separately registered with the server, which is inconvenient. As the number of terminals receiving data from the lighting device increases, the procedure of registration with the server becomes complex.
There is a case where a specific service is provided and the lighting device needs to receive data from the terminal. Thus, a wireless communication module may be embedded in the lighting device. Then, the lighting device is enabled to transmit and receive data by wireless communication while operating as a light source. The lighting device receives attribute information about a light from the terminal or IoT (Internet of Things) devices using the wireless communication module. IoT devices refer to all smart devices and sensors for which IoT technology-based services are intended. The attribute information about the light is information on the brightness of the light, and conceptually includes luminosity, intensity of illumination, luminance, or dimming of the light. The lighting device may adjust the brightness of the light according to the attribute information about the light.
A lighting device may implement the visible light communication function using an intrinsic attribute of the light. However, the conventional lighting device is required to be equipped with both a visible light communication module and a wireless communication module to implement both wireless communication and visible light communication. As a result, the unit price of the lighting device is increased, and ports for outputting the visible light communication signal and the wireless communication signal, respectively, must be employed, which causes inconvenience.
In order to overcome such issues, a lighting device for processing a visible light communication signal and a wireless communication signal in a single module has been introduced. However, this lighting device selectively performs an operation of transmitting a visible light communication signal as a light source and an operation of transmitting a wireless communication signal. Receiving lighting attribute information from an IoT device in real time requires a module for processing the wireless communication signal to continuously operate, but the conventional lighting device cannot operate as a light source in this case.